Muhammad Uzair^*, Salah Al-Kafrawi, Karam Al-Janadi, Ibrahim Al-Bulushi

Energy Engineering, Vol.119, No.1, pp. 83-101, 2022, DOI:10.32604/EE.2022.016411

Abstract This work discusses the importance of monitoring and energy management of green energy resources in order to minimize the negative impacts of electricity generation by regular power plants. The paper introduces a highly efficient, low-cost rooftop photovoltaics (PV) solar panel system which can provide monitoring, controlling and automation. The proposed system is based on Internet of Things (IoT) and can be used to control different utilities in any premises automatically or set by the user-defined priority list, as compared to the existing IoT-based PV systems which can only perform monitoring and maintenance of the PV panels or only certain parameters,… More >

V. Rajkumar^1,*, M. Prakash², V. Vennila³

Computer Systems Science and Engineering, Vol.40, No.2, pp. 779-793, 2022, DOI:10.32604/csse.2022.019622

Abstract Cloud storage is an incipient technology in today’s world. Lack of security in cloud environment is one of the primary challenges faced these days. This scenario poses new security issues and it forms the crux of the current work. The current study proposes Secure Interactional Proof System (SIPS) to address this challenge. This methodology has a few key essential components listed herewith to strengthen the security such as authentication, confidentiality, access control, integrity and the group of components such as AVK Scheme (Access List, Verifier and Key Generator). It is challenging for every user to prove their identity to the… More >

Bo Mi¹, Yuan Weng¹, Darong Huang^1,*, Yang Liu¹, Yuqing Gan²

Computer Systems Science and Engineering, Vol.39, No.2, pp. 265-274, 2021, DOI:10.32604/csse.2021.017507

Abstract PoW (Proof of Work) plays a significant role in most blockchain systems to grant an accounting right over decentralized participants and ensure tamper resistance. Though hash functions are generally exploited for PoW due to their merits on summering, anti-collision, and irreversibility, they cannot certify that the bookkeeper is exactly the worker. Thereafter, such insistence may lead to abuse or even embezzlement of computing power for the benefit of malicious miners. To preserve the functionality of PoW but also bind the miners’ signing keys with their works, we build a post-quantum PoW scheme by changing the approximate closest vector norm for… More >

Sakorn Inthachai¹, Supasit Paengson², Jindaporn Jamradloedluk^1,*, Tosawat Seetawan^2,*

Journal of Renewable Materials, Vol.9, No.10, pp. 1685-1697, 2021, DOI:10.32604/jrm.2021.015553

Abstract A novel roof tile thermoelectric generator (RT-TEG) was used to harvest electrical energy from a solar heat source. The RT-TEG was fabricated and simulated by flat and curved thermoelectric modules consisting of p-n junctions of p-Sb₂Te₃ and n-Bi₂Te₃, with an Al₂O₃ substrate at the top and bottom for heat absorption and heat rejection. The RT-TEG was installed in a roof tile to act as a generator. The electrical voltage and power values of the curved thermoelectric modules were higher than those of the flat thermoelectric module by 0.44 V and 80 mW, at a temperature difference (ΔT) of 100 K.… More > Graphic Abstract

Yingbo Zhang¹, Shi Chen^1,2,*

Energy Engineering, Vol.118, No.3, pp. 707-714, 2021, DOI:10.32604/EE.2021.013888

Abstract In the mining process of coal mine, waterproof coal pillars should be set between the weathered oxidation zone and the first mining face. In order to determine the reasonable upper limit of the first mining face of Hongyi Coal Mine, the waterproof coal pillar needs to be wide enough to resist the lateral hydrostatic pressure of the oxidation zone, and to ensure that the top plate aquifer does not run through the water guide crack zone, while also liberating as much stagnant coal as possible. In this paper, the first coal mine face’s waterproof coal pillar was calculated using conventional… More >

Chanita Mano, Atthakorn Thongtha^*

Journal of Renewable Materials, Vol.9, No.3, pp. 495-506, 2021, DOI:10.32604/jrm.2021.013201

Abstract This work focused on characterizing and improving the thermal behavior of metal sheet roofing. To decrease the heat transfer from the roof into a building, we investigated the efficiency of four types of phase change materials, with different melting points: PCM І, PCM II, PCM III and PCM IV, when used in conjunction with a sheet metal roof. The exterior metal roofing surface temperature was held constant at 50°C, 60°C, 70°C and 80°C, using a thermal source (halogen lights) for 360 min to investigate and compare the thermal performance of the metal sheet roofing with and without phase change materials… More >

Hamidreza Noori¹, Bohayra Mortazavi^{2, 3}, Alessandro Di Pierro⁴, Emad Jomehzadeh⁵, Xiaoying Zhuang^{2, 3}, Zi Goangseup⁶, Kim Sang-Hyun⁷, Timon Rabczuk^{8, 9, *}

CMC-Computers, Materials & Continua, Vol.65, No.3, pp. 2009-2032, 2020, DOI:10.32604/cmc.2020.011256

Abstract In modern physics and fabrication technology, simulation of projectile and target collision is vital to improve design in some critical applications, like; bulletproofing and medical applications. Graphene, the most prominent member of two dimensional materials presents ultrahigh tensile strength and stiffness. Moreover, polydimethylsiloxane (PDMS) is one of the most important elastomeric materials with a high extensive application area, ranging from medical, fabric, and interface material. In this work we considered graphene/PDMS structures to explore the bullet resistance of resulting nanocomposites. To this aim, extensive molecular dynamic simulations were carried out to identify the penetration of bullet through the graphene and… More >

Xinshuai Shi¹, Hongwen Jing^{1, *}, Jianguo Ning², Zhenlong Zhao¹, Junfu Zhu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.1, pp. 315-343, 2020, DOI:10.32604/cmes.2020.07955

Abstract The stability control of gob-side entry retaining in fully mechanized caving face is a typical challenge in many coal mines in China. The rotation and subsidence of the lateral cantilever play a critical role in a coal mine, possibly leading to instability in a coal seam wall or a gob-side wall due to its excessive rotation subsidence. Hence, the presplitting blasting measures in the roof was implemented to cut down the lower main roof and convert it to caved immediate roof strata, which can significantly reduce the rotation space for the lateral cantilever and effectively control its rotation. Firstly, the… More >

Jiali Liu¹, Mengge Yu^{2, *}, Dawei Chen¹, Zhigang Yang³

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 21-30, 2020, DOI:10.32604/fdmp.2020.07658

Abstract In order to investigate how the aerodynamic drag and noise produced by the roof air conditioner of a high-speed train can be reduced, the related unsteady flow in the near-field was computed using the method of large eddy simulation. In this way, the aerodynamic source for noise generation has initially been determined. Then, the far-field aerodynamic noise has been computed in the framework of the Lighthill’s acoustics analogy theory. The propulsion height and flow-guide angle of the roof air conditioner were set as the design variables. According to the computational results, a lower propulsion height or flow-guide angle is beneficial… More >

James D. Barnes¹, Ethan R. Brush¹, Mark S. Newmark¹, Eric E. Ungar^{1, *}

Sound & Vibration, Vol.52, No.4, pp. 6-8, 2018, DOI:10.32604/sv.2018.03737

Abstract Pressure and proximity measurements made in a tunnel indicate that a typical vehicle passage produced on the tunnel roof an initial pressure increase of small magnitude, followed by a sharp and more substantial drop in pressure below atmospheric. The magnitude of the pressure drop was found to increase with smaller clearances between the vehicle top and the tunnel roof, consistent with the Bernoulli relation and the vehicle speed. The dynamic pressures potentially may have significant effects on the vibration and noise environments on the lower floors of “air rights construction” buildings that span highways. More >